# Making bold math symbols more bold

I am writing some equations where I need to distinguish between bold and non-bold quantities. However, for some symbols there is barely any difference when I just use \mathbf or \boldsymbol. Is there a way to 'increase the boldness' of math symbols?

• If you can be more specific about which symbols you find aren't bold enough, probably someone can help. A small compilable example, beginning with \documentclass and ending with \end{document} demonstrating the problem, would be even better. Jun 14 at 19:35
• In particular, do please tell us which math font you employ.
– Mico
Jun 14 at 19:57
• There is also this extensive thread on the subject: tex.stackexchange.com/q/595/118712 Jun 14 at 19:59
• It is hard to distinguish between bold $\alpha$ and $\beta$. I found that the problem is not that the bold is not bold enough, rather that it is bold when it is not supposed to. The problem disappears if I remove the package "mathptmx". Jun 14 at 20:04
• mathptmx is a very old package with very limited font support and no support for bold math symbols at all. There is no reason to use it now Jun 14 at 20:19

In comments it is stated that you are using mathptmx this is an old package targetting the fonts available in early PostScript laser printers. It has no support for bold math.

\documentclass{article}

\usepackage{mathptmx}

\begin{document}

$\alpha$ \boldmath  $\alpha$
\end{document}

produces the warning

Package mathptmx Warning: There are no bold math fonts on input line 7.

If you want a Times-like math font that has support for bold symbols use for example newtxmath or stix2.

\documentclass{article}

\usepackage{newtxtext,newtxmath}

\begin{document}

$\alpha$ \boldmath  $\alpha$
\end{document}
• Thank you very much. I have removed the package. It was part of a template for writing articles in the Journal of Chemical Physics. It looks much better now. Jun 15 at 7:31
• @Physics101 OK but be careful of changing font choices on journal submissions it can invalidate the submission if it messes up the journal production. Jun 15 at 7:33
• Thank you for the advice. The professor that I am working with will read it and help with the formalities before submission. I will ask him for a better template now. Jun 15 at 7:39
• @Physics101 the professor probably won't be much help; the journal might be. Most professors rely on their postdocs or even students to fiddle with that sort of detail Jun 15 at 10:30
• Also, with these packages, you might consider using upright greek letters \upalpha etc. in the bold cases (as \boldsymbol{\upalpha}) for extra distinction. Jun 21 at 7:03

In unicode-math, you can declare a bold math version and use \boldsymbol. XITS Math comes with one, and \setmathfont{XITS Math} will load it automatically for \boldsymbol, \boldmath and \mathversion{bold}. You could also embolden a math font with FakeBold, as in:

\usepackage{unicode-math}
\setmainfont{TeX Gyre Termes}
\setmathfont{TeX Gyre Termes Math}
\setmathfont{TeX Gyre Termes Math}[
version = bold,
FakeBold = 1.2 ]

The one disadvantage of this is that, as of 2021, you cannot combine version= and range=.

In legacy 8-bit TeX, you normally want to load a newer font package that comes in a bold version. You can also declare a bold version for any math alphabet with e.g. \SetMathAlphabet, or a bold version of any math symbol font with \SetSymbolFont (and then optionally use the symbol font as a math alphabet as well, with \DeclareSymbolFontAlphabet). See The LaTeX Font Selection Guide for the full details.